It is known to produce an outer joint part by forming (JP-GBm publication 3-65023).
The constant velocity joint described in the above referenced publication is provided with an outer joint part designed to be substantially cylindrical. No measures are taken to increase the torque transmitting capacity of the joint.
Furthermore, it is known to secure the convoluted boot covering the joint on a radially outwardly pointing flange arranged at the open end of the joint cavity (FR-2592110 A1).
In the above referenced document, the outer circumference of the flange is provided with a groove to ensure an accurate fit of the boot. This means that, at least for providing the groove, it is essential to carry out a turning operation.
It is the object of the present invention to avoid any kind of chip-forming machining in the case of an outer joint part produced from steel plate metal by deep-drawing and to design the outer joint part in such a way that an adequate degree of finish on the outer joint's bearing surfaces is ensured.
In accordance with the invention, the objective is achieved in that the outwardly open end of the cavity of the outer joint part is provided with a radially outwardly pointing collar-shaped flange which remains undeformed during the deep-drawing operation, and thus has the same thickness as the wall of the outer joint part with the groove-free collar-shaped flange serving as a seat for the convoluted boot sealing the joint.
In the case of the constant velocity joint designed in accordance with the invention, the torque transmitting capacity of the outer joint part is substantially increased as a result of the formed-on collar-shaped flange.
Because of the groove-free design of the collar-shaped flange, there is no need for machining the outer circumference of the flange.
In an advantageous embodiment of the invention, the collar-shaped flange is embraced by a thin-walled ring comprising bead-shaped indentations.
According to a further advantageous feature of the invention, the collarshaped flange is arranged at the outer joint part of a ball joint.
And in yet a further advantageous embodiment of the invention, the collarshaped flange is arranged at the outer joint part of a tripod joint.
The advantageous design involving a collar-shaped flange is suitable for both a ball joint and a tripod joint.
According to a further advantageous embodiment of the invention it is proposed that after the outer joint part has been formed and subsequently casehardened and after the inner joint parts have been assembled, the outer joint part should be partially deformed for the purpose of axially securing the inner joint parts.
It has been found that contrary to all expectations, it is possible, after carrying out the case-hardening operations, to subject the outer joint parts to a limited amount of deformation which is sufficient for axially securing the inner joint parts.
According to a further feature of the invention, the constant velocity universal joint comprises an inner joint part with inner running grooves corresponding to the outer running grooves and having torque transmitting balls which are received in the inner and outer running grooves and which are held in the windows of a cage guided between the outer joint part and inner joint part, with the outer joint part, at the open axial end of its cavity between the outer running grooves, being radially inwardly deformed. This measure ensures that the cage and thus the inner joint part are secured axially outwardly.
In a further embodiment of the invention, the constant velocity universal joint comprises an outer joint part with axially extending guiding grooves arranged parallel relative to one another and comprising Two guiding faces facing one another, as well as an inner joint part with radially arranged arms corresponding to the guiding grooves, with each of the arms via a roller assembly, being in contact with an associated guiding groove and with the outer joint part, at the open end of its cavity in the region of the guiding faces, being provided with deformed regions pointing towards the center line of the guiding grooves.
In this way, the inner parts of a tripod joint are also secured axially.